This great visual gag is very much a metaphor for the career of writer-director Damien Chazelle, who made his feature-length debut with the small-scale but powerful Whiplash. Having also co-written the similarly low-key 10 Cloverfield Lane, Chazelle is now ready for a larger venue (on screen and off, as La La Land was chosen to open the Venice Film Festival).

Chazelle’s second directorial effort is a literal journey towards greater glory, as the opening sequence features dozens of hopeful young people singing and dancing right in the middle of a traffic jam on the freeway, on their way to Los Angeles. Here the dreams and aspirations of two people in particular will collide in interesting ways: Mia (Emma Stone) is an aspiring actress and playwright who’s stuck working as a barista on the Warner Bros. studio lot, while Sebastian (Ryan Gosling) is a jazz pianist whose romanticised view of the craft is at odds with an ever-changing reality.

The two young stars, who still share the chemistry they had in Crazy Stupid Love, dominate proceedings with a panache that is joyfully infectious, and are pretty much the only major names in the cast save for a supporting turn by singer John Legend and a cameo by J.K. Simmons (who, rather disappointingly, does not get to properly participate in any of the musical numbers). This is because Chazelle is not interested in filling the screen with famous faces. What matters to him is the music.

Jazz already played a huge role in Whiplash, and it takes centre-stage again, merging perfectly with what is essentially a love letter to the great Hollywood musicals of yore, the kind that would occupy the very same studio space that becomes a character in La La Land. The singing and dancing is uniformly exquisite, albeit with some deliberate rougher edges that add an extra charm (Gosling, in particular, looks and sounds slightly less polished during these routines than one might expect).

As the title suggests, this story unfolds in a world of its own, one where dreams and reality coexist and blend seamlessly to create a very specific vintage mood, to the extent that any romantically inclined viewer could realistically expect Gene Kelly to join the party. The timelessness is also reflected in Emma Stone’s performance, with her peculiar charisma shining through in an exhilarating and occasionally heartbreaking manner.

After Berlin’s Hail, Caesar! and Cannes’ Café Society, it’s safe to say the connective tissue between all three major festival openers this year – with Toronto’s upcoming The Magnificent Seven deserving a special mention – has been a genuine passion for the Hollywood of old. But where the Coen brothers and Woody Allen aimed to somewhat deconstruct the magic, Chazelle embraces it fully, delivering a glorious extravaganza that proudly wears its heart on its sleeve. They truly don’t make them like this anymore.